Delta Airlines is the most popular airline and legacy carrier in the United States. oldest airline in the world. Delta head office Atlanta, Georgia. Delta Airlines Founded, March 2, 1925, 5400 Delta Flights Daily visits in 52 countries and 325 destinations, Delta airline currently 9 hubs. Atlanta, Boston, Los Angeles,Minneapolis/St. Paul, New York-JFK, New York–LaGuardia, Salt Lake City, Detroit, Seattle.